An article exposed to the dynamic stresses and thus also to wear as well as noise development is for example a band, belt, hose, air spring lobe, compensator or multilayered web of which the belt in the form of a drive belt is of particular relevance. The elastic foundational body of the drive belt comprises a top ply as belt backing and a substructure with a force transmission zone. For this, reference is made particularly to the following patent literature: DE 38 23 157 A1, DE 10 2006 007 509 A1 (United States patent application publication US 2008/0261739), U.S. Pat. No. 7,749,118, United States patent application publication US 2008/0032837, U.S. Pat. Nos. 3,981,206 and 5,417,618.
Drive belts in particular are coated with a coating in the region of the force transmission zone in particular for noise reduction and also enhanced abrasion resistance. The prior art in this respect is:                Use is made of a flocked cover ply, particularly in the form of a cotton or aramid flock, or of a thin elastic polymeric layer filled with fibers (aramid fibers for example), for example as described in unexamined application DE 38 23 157 A1, wherein the flocked cover ply is usually attached by means of a solution. However, this coating is not durable with some engines. Moreover, noise problems occur with some engines in the case of moisture.        A loop-drawingly knitted textile cover ply, for example as described in U.S. Pat. No. 3,981,206 is used. The disadvantage here is that test engines give rise to noise in the presence of moisture.        A textile cover ply in the form of a formed-loop knit fabric is used. Unexamined application DE 10 2006 007 509 A1 in particular is cited in this regard. The warp-knit fabric consists of a first yarn, more particularly composed of a polyamide (PA) or polyester (PES), and of a second yarn, more particularly composed of a polyurethane (PU). Again the disadvantage is that test engines give rise to noise in the presence of moisture.        In a more recent development described in DE 10 2008 012 044.8, a self-supporting film/sheet (of PTFE for example) or a film/sheet laminate (a PA PTFE film/sheet laminate for example) is used instead of textile cover plies or in combination therewith, particularly under the aspect of rendering a drive belt oil resistant.        
However, the research and development focus is on textile cover plies, which also form the basis for the underlying generic article, in particular a drive belt.
In what follows, the issues surrounding the coefficient of friction (COF) are more particularly discussed in connection with the various coating systems.
Hitherto, various coating systems have been used for different COF target values, see the abovementioned embodiments according to the prior art. Certain properties in respect of durability, noise behavior and coefficient of friction result therefrom as a compromise. The coefficient of friction is subject to fluctuations even in virgin parts, and will in some instances change appreciably in the course of the use life of an article, particularly in the case of a drive belt. Particular coefficients of friction, desired by the customer for various reasons, are therefore very difficult to achieve, if at all.